Réponse :
Explications étape par étape :
bonjour
(5/7)/(7/4) = 5/7 × 4/7 = 20/49
x = 20/49
x - 1 = 20/49 - 1 = 20/49 - 49/49 = -29/49
1/( x -1) = 1/ ((-29)/49) = 49/(-29)
x = 20/49
x² = (20/49)² = 20²/49² = 400/ 2401
1/x² = 1 /((400/2401) = 2401/400
x = 20/49
x + 1 = 20/49 + 1 = 20/49 + 49/49 = 69/49
1/(x+ 1) = 1 / (69/49) = 49/69
x = 20/49
1 - x = 1 - 20 /49 = 49/49 - 20/49 = 29/49
1/(1 - x) = 1 /(29/49) = 49/29
